Galapagos Shearwater, Puffinus subalaris

The Galapagos Shearwater (Puffinus subalaris) is a petite shearwater. Until recently, it was considered to be a subspecies of Audubon’s Shearwater, but it is actually one of two members of a very ancient lineage of the small Puffinus species, the other being, as indicated by mtDNA cytochrome b sequence data, the Christmas Shearwater. It’s an endemic breeder of the Galapagos Islands, and is largely sedentary, although individuals are frequently seen as far as the Oaxacan coast of Mexico.

The Galapagos Shearwater has dark brown upperparts, under tail, and underwing flight feathers, the rest of the underparts plumage is white. Sometimes, it has a dark collar. The female and the male are similar, as are the young after fledging. Having a slender body, it is about 29 to 31 cm long. It has a wingspan of around 63 cm and weighs 123 to 225 g. The species closely resembles the Tropical Shearwater, although the latter is typically a darker black and has a longer tail.

It is a gregarious species and will feed at sea with other shearwaters and boobies. It flies low over the water and feeds on squid, fish, and offal. It intersperses 4 to 10 stiff wing beats with shallow glides.

Image Caption: Galapagos Shearwater (Puffinus subalaris). Credit: Dominic Sherony/Wikipedia (CC BY-SA 2.0)